Update app.py

app.py

@@ -47,7 +47,8 @@ class DMButton(Button):
 
     async def callback(self, interaction: discord.Interaction):
         # await interaction.user.send(self.message) # this is for DMs, but users may have DMs disabled
-        del user_tokens[int(self.user_id)] # always delete all past tokens when creating new link
+        if int(self.user_id) in user_tokens:
+            del user_tokens[int(self.user_id)] # always delete all past tokens when creating new link
         unique_string = generate_unique_string()
         user_tokens[self.user_id] = unique_string
         unique_link = f"{GRADIO_APP_URL}?user_id={self.user_id}&token={unique_string}"